Good news for Cardinals on Kolb, Wells

Three critical injury situations in the Arizona Cardinals' offensive backfield appear to be improving.

Quarterback Kevin Kolb, sidelined by a chest injury after four pass attempts during the team's exhibition opener Sunday, was throwing during the team's walk-through session Tuesday, Kent Somers reported.

Starting running back Beanie Wells, sidelined by knee surgery after topping 1,000 yards rushing in 2011, was activated off the physically unable to perform list, the team announced.

Backup running back Ryan Williams -- the term "backup" doesn't do him justice relative to the Cardinals' expectations for him -- remains on course in his rehabilitation from surgery to repair a torn patella. Williams did not play Sunday, but he has looked good in practice.

Any positive news on these three key injury fronts is welcome, of course. It's a little concerning, however, when a team goes into a season with injury concerns to three players so central to its plans.